Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Net Oxygen and Carbon-Dioxide Balances in Solutions Bathing Roots of Wetland Plants

Barbara L. Bedford, David R. Bouldin and Bethany D. Beliveau
Journal of Ecology
Vol. 79, No. 4 (Dec., 1991), pp. 943-959
DOI: 10.2307/2261090
Stable URL: http://www.jstor.org/stable/2261090
Page Count: 17
  • Read Online (Free)
  • Download ($18.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Net Oxygen and Carbon-Dioxide Balances in Solutions Bathing Roots of Wetland Plants
Preview not available

Abstract

(1) A procedure and experimental apparatus are described that permit determination of oxygen and carbon-dioxide generation in nutrient cultures bathing roots of mature wetland plants. Roots of five different species were isolated from the atmosphere so that the only significant route of gaseous transfer was through the plant itself. (2) At the level of the whole plant, and on a time scale of weeks, the net effect of wetland plants on the root environment was generally not to oxygenate it. Although plants transported large amounts of oxygen between shoots and roots, most of that oxygen was consumed before it reached the bulk solution. Oxygen content of solutions bathing the root systems typically remained at or below 31 μ moll-1. However, solutions were greatly enriched in carbon dioxide, containing c. 1-5 mmoll-1. The data are consistent with the hypothesis that the plants transported large amounts of O2 to the roots but that most of the O2 was consumed by respiration within the plant or by microbes supported by carbon compounds derived from the plant. (3) Rates of oxygen generation within root zone solutions generally were well below 35 μ mol O2 plant-1 day-1 for most experimental plants. Only Scirpus acutus generated oxygen in solution at rates as high as 58 μ mol O2 plant-1 day-1. (4) Microscopic analysis of roots revealed a high proportion of cortical aerenchyma (40-48%) in 86-99% of the sampled lengths of primary roots.

Page Thumbnails

  • Thumbnail: Page 
943
    943
  • Thumbnail: Page 
944
    944
  • Thumbnail: Page 
945
    945
  • Thumbnail: Page 
946
    946
  • Thumbnail: Page 
947
    947
  • Thumbnail: Page 
948
    948
  • Thumbnail: Page 
949
    949
  • Thumbnail: Page 
950
    950
  • Thumbnail: Page 
951
    951
  • Thumbnail: Page 
952
    952
  • Thumbnail: Page 
953
    953
  • Thumbnail: Page 
954
    954
  • Thumbnail: Page 
955
    955
  • Thumbnail: Page 
956
    956
  • Thumbnail: Page 
957
    957
  • Thumbnail: Page 
958
    958
  • Thumbnail: Page 
959
    959